scholarly journals Efficient removal of three dyes using porous covalent triazine frameworks: adsorption mechanism and role of pore distribution

2020 ◽  
Vol 82 (12) ◽  
pp. 3023-3031
Author(s):  
Fengxia An ◽  
Jingliang Liu ◽  
Zhaoyi Xu ◽  
Shourong Zheng
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Ph Dependence ◽  
Batch Adsorption ◽  
Spectroscopic Techniques ◽  
Adsorption Mechanisms ◽  
Bonding Interaction ◽  
Adsorption Affinity

Abstract Dyes are widely used in production and life. In this study, porous covalent triazine frameworks (CTFs) were synthesized and the adsorption behavior for three dyes was investigated by batch adsorption experiments. CTFs were characterized by various spectroscopic techniques for structure, porosity and surface properties. Several possible adsorption mechanisms were proposed including pore-filling, electrostatic attraction and hydrogen bonding interaction with the triazine structure of CTFs. The mechanisms were further verified by the pore size distribution and pH dependence. Additionally, CTFDCBP displayed stronger adsorption affinity and faster adsorption kinetics for dyes, because of the wide pore size distribution. This study provides a new insight into the mesoporous CTFs, which exhibit great potential as an effective adsorbent for dye removal.

A Realistic Method to Describe the Role of Diffusion in Catalyst Design

2009 ◽  
Vol 294 ◽  
pp. 65-76
Author(s):  
Mohammad Ebrahim Zeynali
Keyword(s):  
Grain Size ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Nitrate Solution ◽  
Effective Diffusivity ◽  
Catalyst Design ◽  
Internal Surface Area ◽  
Co Precipitation

The dehydrogenation of diethylbenzene to divinylbenzene is a catalytic reaction. The catalyst for the dehydrogenation was prepared by co-precipitation of iron and chromium hydroxide from nitrate solution, followed by doping with potassium carbonate and drying. To make available the internal surface area of the catalyst for the reactant, the pores must be of the proper sizes to allow the reactant to diffuse and penetrate inside the catalyst pellets. The prepared catalyst was considered as a model for investigating the role of diffusion in catalyst design. In this study, different mechanisms of diffusion, such as Knudsen and bulk, were investigated for the case of diethylbenzene diffusion into the catalyst and it was concluded that the pore sizes should be in a range that permits transitional diffusion (both Knudsen and bulk diffusion). The catalyst grain size can be controlled and varied by acting on parameters such as the speed and time of mixing, type of alkali, temperature and pH. Particle size distribution experiments were conducted for different types of alkali and speeds of mixing in order to characterize the catalyst. The effects of the grain size, formed during co-precipitation, upon the pore size distribution of the catalyst pellet which affects the effective diffusivity were discussed. The pore size distribution of the model catalyst was obtained and the effective diffusivities were calculated by numerical integration of the Johanson-Stewart equation.

The role of beaded activated carbon’s pore size distribution on heel formation during cyclic adsorption/desorption of organic vapors

2016 ◽  
Vol 315 ◽  
pp. 42-51 ◽  
Author(s):  
Masoud Jahandar Lashaki ◽  
John D. Atkinson ◽  
Zaher Hashisho ◽  
John H. Phillips ◽  
James E. Anderson ◽  
...  
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Organic Vapors ◽  
Cyclic Adsorption ◽  
Adsorption Desorption

Gelatin–carrageenan hydrogels: Role of pore size distribution on drug delivery process

2014 ◽  
Vol 113 ◽  
pp. 346-351 ◽  
Author(s):  
Jina Susan Varghese ◽  
Nisha Chellappa ◽  
Nishter Nishad Fathima
Keyword(s):  
Drug Delivery ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution

scholarly journals Pore size distribution in soils irrigated with sodic water and wastewater

2010 ◽  
Vol 34 (3) ◽  
pp. 701-707 ◽  
Author(s):  
Roberta Alessandra Bruschi Gonçalves ◽  
Thomas Vincent Gloaguen ◽  
Marcos Vinicius Folegatti ◽  
Paulo Leonel Libardi ◽  
Yves Lucas ◽  
...  
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Water Retention ◽  
Sandy Loam ◽  
Domestic Wastewater ◽  
Treated Wastewater ◽  
Soil Infiltration ◽  
Sodic Water

Soil porosity, especially pore size distribution, is an important controlling factor for soil infiltration, hydraulic conductivity, and water retention. This study aimed to verify the effect of secondary-treated domestic wastewater (STW) on the porosity of a sandy loam Oxisol in the city of Lins, state of São Paulo, Brazil. The two-year experiment was divided into three plots: soil cultivated with corn and sunflower and irrigated with STW, soil cultivated and irrigated with sodic groundwater, and non-irrigated and non-cultivated soil (control). At the end of the experiment, undisturbed core samples were sampled from 0 to 2.0 m (8 depths). The water retention curves were obtained by tension plates and Richard's pressure plate apparatus, and the pore size distribution inferred from the retention curves. It was found that irrigation with treated wastewater and treated groundwater led to a decrease in microporosity (V MI), defined as the pore class ranging from 0.2 to 50 μm diameter. On the other hand, a significant increase in cryptoporosity (V CRI) (< 0.2 μm) was identified throughout the soil profile. The presence of Na+ in both waters confirmed the role of this ion on pore size distribution and soil moisture (higher water retention).

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